Christ



C. F. GILCHRIST.

DRIVING NIECHANISM.

APPLICATION man fun/22, |918.

1 ,429,028. PatentedSept. 12, 1922.

Patented Sept. 12, `1922. i

UNITED STATES PATENT OFFICE.

CLARENCE F. GILCHRIST, OF TOLEDO, OHIO, ASSIGNOR TO THE ELECTRIC AUTO-LITE COMPANY, OF TOLEDO, OHIO, A. CORPORATION F OHIO.

L DRIVING MECHANISM..

' Application nieu July 22, i918. serial No. 246,189.

To all whom it may concern:

Be it known that I, CLARENCE F. GIL- oHRIsT, a citizen of the United States, residingat Toledo, in the county of Lucas and State of Ohio, have invented certain new and usefulImprovements in Driving Mechanism, of which I declare the following to be a full, clear, and exact'description.

This invention relates to a driving mechaism for use in the starting system of an internal combustion engine. More particularly considered, the invention comprises an automatic screw gearing applicable in the gear train intermediate the electric starting i5 motor and internal combustion engine;`

` An object of this invention is to provide a driving mechanism intermediate the electric motor and engine, which has flexibility and elasticity, and in which there is no spring or similar elastic member in the direct line of ower transmission.

Another object is to provide a type of gearing in which the driving connection and disconnection is made in an entirely automatic way.

Another object is to utilize a gearing unit which will automatically take care of variations in engine cylinder compression.

Further objects of this'invention relate to economies of manufacture and details of construction as will hereinafter 'appear from the detailed description to follow. I accomplish the objects of my invention in one instance by the devices and means described in the following specification, but it is evident that the same may be varied widely without departing from the scope of the invention as pointed out in the appended claims. A structure constituting one em- 40 bodiment of my invention, which may be the preferred, is illustrated in the accompanyin drawings forming a part thereof, in w ich: y

Figure I is a longitudinal sectional view taken through the gearing unit showing it in its disconnected position.

^ Figure II is a view similar to Fig. I but showing Vthe unit in its connected position.

Figure III is a cross sectional view of 50 the driving unit, taken on the line III-III ,of Figure l Figure IV is an elevation of an elementof the rdrivin unit; and 1 t Figure V is another elevation of the element, shown in Figure IV,

l,hereinafter described, a central section 5 of Similar reference numerals refer to similar parts throughout the several views, and the cross sectional view is taken looking in the direction of the arrows.

In accordance With the drawings, I have shown an engine element l, which in the present invention takes the form of the ily-Wheel adapted to be directly connected to the crank shaft of an internal combustion engine. An electric motor 2 is positioned relative to the ily-Wheel, so as to have operative connection therewith. The motor may be of an type effective for the efficient starting of t e engine, such as the series wound. type commonly used in this connection. rEhe motor has a driving shaft 3 which is machined to have three sections of different diameters, a short section 4l, adjacent the motor, forming a stop for the driving unit, as

less diameter than the section el, and an outer section 6, of less diameter than the central section. The end of the outer section 6 is screw threaded as indicated in Figures I and II, and with this threaded portion an internally threaded. sleeve 'Y is adapted to have threaded engagement, thereby having axial movement relative to the shaft. The outer end of this sleeve 7 is externally threaded to receive a holding nut 8, and adjacent its inner end the sleeve carries a pin 9 extend' ing radially therefrom. From the point of attachment of the pin to the inner end of the sleeve, the internal diameter of the sleeve is increased above that of the threaded portion and machined so as to have a smooth cylindrical surface as shown at l0 in Figure I. The pin extends into the recess formed by this greater diameter of the sleeve, and is adapted to abut against the inner end ofy thevthreaded section of the shaft, preventing the removal of the sleeve from the shaft. lThe diameter of this inner end of the sleeve is such` that the sleeve readily slides over the middle sectionof the shaft when the sleeve 100 is moved axially toward the motor.

Mounted upon the sleeve 7 is a second sleeve 12, which has a length relatively less than that of the first named sleeve, and which is adapted to have axial and rota- 105 `tional movement relative to the sleeve 7.

In the body 4of the sleeve, an angular slot 13`is`cut in such a position that its direction relative to the axis of the cylinder or sleeve opposes that of the inclination of the screw l to have movement.

threads on `the* motoi sha-ft, and in such ak manner that the slot advances toward the inner end of the shaft. `The slot 13 does not extend completely around the sleeve," but takes the :term of a section or a' spiral or screw thread, the inner end 14. of whichr lies adjacent the one-end of the sleeve, and thek outer end l5 of which lies approximately mid-way between the ends of the slee-ve, as clearly illustrated in Figure 1V and V.` `In the slot .l-3, the pin 9 is adapted The inner end of the sleeve 12 is outturned to iorm an annular tlangeli, and this flange is cut to :torni a series ot lugs 18,

equally spaced from each other as shown at Figure III. Mounted on the middle section of the shaft, is a pinion 1f), which is normally in juxtapositionwith the surface formed by the annular flange and lugs 17 and 18. A holding ring 2O is fixed to the periphery of the pinion, adjacent the outer end thereof, for a purpose to be described.

The i'esilient element of the driving unit is a coil spring 21, which is placed around thesleeves 7 and 12 in such a position that the inner end thereof abuts against the an nular {iange 17 -of the outer sleeve. The outer end of the spring bears against the circular stop or washer 2Q, which is held in position adjacent the end of the motor shaft by the terminal nut 8, hereinafter described. The washer 22 serves also as the support for a cylindrical casing 23 -which is attached thereto by means of machine screws Q4. This cylinder extends over the resilient element, and its inner end is slotted to 'form a series of parallel fingers 25, between which the projecting lugs 17 are adapted to have longitudinal movement. The ends of these fingers are turned down in such. away that they insert over the annular ring 20 on the` outer end or' the pinion, and between thevarious teeth of the pinion, so that rotational force applied. to lthe cylinder 23 is at once transmitted to the pinion by means of the beat-in fingers 25.

The normal inoperative position of the driving mechanism is illustrated in Figure I of the drawing, When power is applied y to the motor, and assuming that thedirectionof rotation ofthe motor shaft is vas indicated by the vsmall curved arrow, the inertia of `the, driving unit permits a screwing thepinion to move axially `inward toward ,the enginegear 1.` Because of the inertia of the driving element, there willbe nov rotation of the pinion, and in-consequence, the meshing vof pinion and gearis readily ef- `fected.4 Axial movementiot the pinionfcony tinues until it comes into abutment with the collar 4 of the motor shaft. i ,y .It isevident that the rotational 'force `of `the motor must be appliedgradually to the tion of rotation of theinotor shaft, and' since the inclination of the slot is such that the rotating pin exertsy a camming'force upon the sleeve 12, tending to move it in an outer direction, the spring 2l is compressed until the inertia of the engine member is overcome, or the outer endof the sleeve 1'2 comes in contact with the terminal washer 2Q, By the time the full compression of the spring,r has been completed,'thebalance of forces between the passive engine element and the active motor element, will have been `gradually4 attained, soy that the engine may be started without any destructive or harmful results to the ,variousv parts of the mecha nism.v It should be noted that the'driving intermediate the motor and engine" meniber is from motor shaft to the inner sleeve, the inner sleeve to the outer sleeve, the outer sleeve to the connecting fingers 25, and from the fingers to the pinion and from thepinion to the engine gear. ,In other words, the spring does not directly transm'itthe 4driving torque of the motor but produces the necessary reaction betweenthe pin and the wall of the slot and serves as a buffer for takingr the jaar, due to the sudden application' of the rotational force of the motor.

While .l have described my .invention in more or less d etail, andas being einboi'ded incertain precise forms I do not desire or intend te be limitedthereto, as on the contrary my invention contemplates broadly all proper changes,as well asthe omission of immaterial elements and .thesubstitution of equivalents` therefor, as .circumstances mayy suggest or necessity renderexpedient.

Having thus described invention, what y I claim as new and'wdesirete secure byLetcombustion` engines,`the combination'of an i engine member; .a driving shaft havin `a motion upon the` motor shaft which causes threaded portion; an" internally threa ed sleeve havingv threaded, engagement; with said shaft; a pinyin saidsleeveiadjacent an4 end thereof; aisee/ond sleeve havingiJ slot circumferentially spaced lugs at-one end thereof; a'pinion slidably mountedv onsaid shaft, having aringfat oney end thereof; a

spring mounted on said sleeves and adapted iso to exert pressure on said radial lugs; and a casing, one end of which is cut to form axially extending fingers between which the lugs are adapted to have axial movement, the ends of said fingers being in-turned over said ring to engage the teeth of the pinion, said slot forming a camming surface for the pin whereby the spring is compressed when the pinion has full enmeshment with the engine member.

2. In a Starting mechanism for internal combustion engines, the combination of an engine member; a driving shaft, a portion of which is threaded; a sleeve having threaded engagement with said shaft; a pin in said sleeve; a second sleeve mounted on said first named sleeve, having a camming slot in its wall in which the pin is adapted to ride; a pinion mounted on said shaft; connections intermediate the pinion and said second sleeve; resilient means operative to oppose the camming movement of said slot when the pinion has moved into complete engagement with said engine member.

3. In a starting mechanism for internal combustion engines, the combination of an engine member; a driving shaft, a portion of which is threaded; a sleeve having threaded engagement with said shaft; a pin in said sleeve; a second sleeve mounted on said first named sleeve, having a camming slot in its wall in which the pin is adapted to ride; and a flange having radially extending lugs; a pinion on said shaft adapted to make connection with said engine member; a casing attached to said first named sleeve having inwardly projecting fingers integral therewith, said iingers being adapted to have sliding engagement with said lugs and said pinion whereby a positive drive may be obtained from the second named sleeve to the pinion; and resilient .means operative to oppose the camming movement of said slot when the pinion has moved into complete engagement with said engine member.

4. In a starting mechanism for internal combustion engines, the combination of an engine member; a driving shaft, a portion of which is threaded; a sleeve having threaded engagement with said shaft; a pin in said sleeve; a second sleeve mounted on said first named sleeve, havinff a camming slot in its wall in which the pin is adapted to ride; resilient means for opposing relative movement of said sleeve in one direction; a pinion mounted on said shaft; means operatively connecting said pinion and sleeves, said pinion being adapted to have automatic axial movement into and out of engagement with the engine members.

5. n an engine starting mechanism, the combination of an engine member, a motor driven shaft, a driving member carried thereby, means screw-threaded on said shaft for initially moving said driving member into engagement with said engine member, and means comprising a resilient compression member and a cam mechanism for sub sequently transmitting a yielding driving orque from said shaft to said engine mem- 6. In an en 'ne starting mechanism, the combination o an engine member, a motor driven shaft, a pinion having a bearing thereon, a member having threaded engagement with said shaft, means comprising a cam device and a resilient member for operativel connecting said pinion and said first member whereby upon initial rotation of the shaft the pinion is shifted into engagement with the engine member and upon further rotation the pinion yieldingly drives the engine member.

7 In an en ine starting mechanism, the combination o an engine member, a motor driven shaft, a driving member thereon for said engine member, means for operatively connectin said shaft and said driving member including a sleeve screw threaded on said shaft, a cam device between said sleeve and said pinion and a resilient member for varying the reaction between the co-operating parts of said cam device in accordance with the relative movement thereof.

In testimony whereof, I affix my signature.

CLARENCE F. GILCHRIST. 

